<div class="bg">
  <div class="left">
    <div class="left-box" (mouseup)="MovingSNodeIntoTree(0)"></div>
    <div class="left-box" (mouseup)="MovingSNodeIntoTree(1)"></div>
  </div>
  <div class="right" (mouseup)="MovingSNodeIntoTree(2)"></div>
</div>
